The Green Bay Packers might be losing rookie receiver Jared Abbrederis for the season because of a knee injury but received good news about center Corey Linsley's shoulder injury.

Both players, who are fifth-round draft picks, finished practice Thursday but sat out Friday morning. The Milwaukee Journal-Sentinel reported Friday afternoon that the Packers' initially diagnosed Abbrederis' injury as a torn anterior cruciate ligament, which is a season-ending injury. However, Abbrederis was scheduled for further medical tests to confirm.

A source familiar with Linsley's injury said the backup center was fine and should be able to participate in the Packers' Family Night practice Saturday.

Abbrederis' injury is reminiscent of right tackle Bryan Bulaga's season-ending torn ACL last year. Bulaga injured his knee on Family Night but finished the practice. The next morning his knee was sore and the team's medical staff determined he had a partially torn ACL that required surgery.

When asked late Friday morning if he feared Abbrederis had a torn ACL, Packers coach Mike McCarthy grew testy.

"I haven't had time to sit down with the medical staff," he said. "Right now, he has a knee. He completed practice (Thursday)."

Both players are off to promising starts in training camp, so a serious injury to either would be a big setback. Abbrederis is fighting for the Nos. 5 or 6 roster spot at receiver and has made enough plays a week into camp to suggest he has a good chance to make the team as a rookie.

Linsley moved from the No. 3 center to No. 2 early in camp, and signs suggest he could be a viable player as a rookie. However, the Packers' depth at center behind him and starter JC Tretter is thin. The only other true center on the roster is Garth Gerhart, who has spent parts of the last two seasons on the team's practice squad.

The other backup centers are T.J. Lang, who's a guard by trade, and Don Barclay, who has played only guard and tackle this year after experimenting as a backup center in 2013.

"(Linsley) has done some really good things," McCarthy said. "I think he's stood out in particular the one-on-one drills. And hopefully this (injury) is not something long."